Full Stack Engineer

You are given an undirected tree. Your task is to find the longest path in the tree.

The longest path in a tree is defined as the maximum number of edges between any two nodes. You are given a 2-dimensional array ‘Edges’ in which ‘Edges[i][0]’ and ‘Edges[i][1]’ contains an edge.

For Example:

In the example below, the longest path is between nodes 1 and 3. The length of the path is 3 since the number of edges between node 1 and node 3 is 3. Hence, the answer is 3.

You have been given a Binary Search Tree of integers with ‘N’ nodes. You are also given data of a node of this tree. Your task is to delete the given node from the BST.

A binary search tree (BST) is a binary tree data structure that has the following properties:

• The left subtree of a node contains only nodes with data less than the node’s data.

• The right subtree of a node contains only nodes with data greater than the node’s data.

• Both the left and right subtrees must also be binary search trees.

Example:

For the given BST, if we want to delete the node with data 5 :

The modified BST will be:

Please notice that another valid answer is:

Note :

1. The node which we want to delete will always be present in the given tree.

2. If after deletion the tree becomes empty, print -1.

You are given a multi-level linked list of 'N' nodes, each node has a next and child pointer which may or may not point to a separate node. Flatten the multi-level linked list into a singly linked list. You need to return the head of the updated linked list.

Example:

Flatten :

All the different rows are merged into a single row.

You are given a list of “N” strings A. Your task is to check whether you can form a given target string using a combination of one or more strings of A.

Note :

You can use any string of A multiple times.

Examples :

A =[“coding”, ”ninjas”, “is”, “awesome”]  target = “codingninjas”
Ans = true as we use “coding” and “ninjas” to form “codingninjas”